diff --git a/src/crypt_zip.c b/src/crypt_zip.c
index 42abe93..b11d7a3 100644
--- a/src/crypt_zip.c
+++ b/src/crypt_zip.c
@@ -114,7 +114,8 @@
     cryptstate_T *state,
     char_u	*from,
     size_t	len,
-    char_u	*to)
+    char_u	*to,
+    int		last UNUSED)
 {
     zip_state_T *zs = state->method_state;
     size_t	i;
@@ -137,7 +138,8 @@
     cryptstate_T *state,
     char_u	*from,
     size_t	len,
-    char_u	*to)
+    char_u	*to,
+    int		last UNUSED)
 {
     zip_state_T *zs = state->method_state;
     size_t	i;